miR-9-5p Exerts a Dual Role in Cervical Cancer and Targets Transcription Factor TWIST1

Research progress on human papillomavirus-negative cervical cancer: A review

Cervical cancer is the fourth most common cancer in women worldwide. The vast majority of cervical cancers are associated with human papillomavirus (HPV) infection, but a small proportion of cervical cancers occur independently of HPV infection, with different subtypes having varying rates of occurrence. Despite the presence of false negatives in current testing, improving the accuracy of detection is crucial for studying the pathogenesis of HPV-negative cervical cancer and improving the prognosis of these patients. Existing research suggests that HPV-negative cervical cancer has a different pathogenesis from HPV-positive cervical cancer, although the exact mechanism is not yet clear. It is currently believed to be associated with the immune microenvironment, certain tumor gene mutations, and some long noncoding RNAs. This article provides an overview of the latest research progress on HPV-negative cervical cancer, including possible reasons, pathogenesis, pathological features, and clinical characteristics, aiming to provide new insights for diagnosis, treatment, and prognosis improvement.

The role of microRNA-9 in ovarian and cervical cancers: An updated overview

Ovarian and cervical cancers are the two most frequent kind of gynaecological cancers (GCs). In spite of advances in prevention, screening and treatment, cervical cancer still leads to an increased morbidity and mortality worldwide. Ovarian cancer is often detected at a late stage, which significantly reduces the effectiveness of available treatments. Therefore, novel methods are desperately needed to improve the clinical care of GC patients. MicroRNAs, also known as short noncoding RNAs (miRNAs/miRs), are a diverse group of RNAs with a length of 22 nucleotides. These typically cause translational repression and mRNA degradation by interacting with target mRNAs' 3' untranslated region (3'-UTR), together with other regions and gene promoters. Under certain conditions, they are also able to activate translation or regulate transcription. It has been demonstrated that miRNAs are crucial to several biological processes leading to tumorigenesis, including GCs. Recent research has shown that miR-9 affects carcinogenesis. In this review, we will provide an overview of current research on the potential utility of miR-9 in the diagnosis, prognosis, and therapy of ovarian and cervical malignancies.

Potential diagnostic value of miRNAs in sexually transmitted infections

MiRNAs are small endogenous non-coding RNAs that have been demonstrated to be involved in post-transcriptional gene silencing, regulating a number of metabolic functions in the human body, including immune response, cellular physiology, organ development, angiogenesis, signaling, and other aspects. As popular molecules that have been studied in previous years, given their extensive regulatory functions, miRNAs hold considerable promise as non-invasive biomarkers. Sexually transmitted infections(STIs) are still widespread and have an adverse effect on individuals, communities, and society worldwide. miRNAs in the regulatory networks are generally involved in their molecular processes of formation and development. In this review, we discuss the value of miRNAs for the diagnosis of STIs.

Linc01116 Silencing Inhibits the Proliferation and Invasion, Promotes Apoptosis of Chordoma Cells via Regulating the Expression of Mir-9-5p/PKG1

BACKGROUND

Long intergenic non-protein coding RNA 1116 (LINC01116) plays a carcinogenic role in a variety of cancers. The study aims to investigate the roles of LINC01116 and hsa-miR-9-5p (miR-9-5p) and fathom their interaction in chordoma.

METHODS

The predicted binding sites between miR-9-5p with LINC01116 and phosphoglycerate kinase 1 (PGK1) by starBase were confirmed through dual-luciferase reporter assay. The behaviors of chordoma cells undergoing transfection with siLINC01116 or miR-9-5p inhibitor were determined by Cell Counting Kit-8 (CCK-8), colony formation, Transwell, and flow cytometry assays. The glucose consumption, lactate production, and adenosine triphosphate (ATP) production of chordoma cells were examined with specific kits. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to determine relevant gene expressions in chordoma cells.

RESULTS

Silencing of LINC01116 facilitated the apoptosis and expressions of Bcl-2- associated X (Bax), cleaved caspase-3 (C caspase-3) and miR-9-5p while repressing the cell cycle, viability, proliferation, invasion, glucose consumption, lactate production, ATP production, and expressions of PGK1 and Bcl-2. Meanwhile, LINC01116 sponged miR-9-5p, which could target PGK1. Moreover, the miR-9-5p inhibitor acted contrarily and reversed the role of siLINC01116 in chordoma cells. Besides, LINC01116 downregulation facilitated apoptosis and attenuated the proliferation and invasion of chordoma cells as well as PGK1 expression by upregulating miR-9-5p expression.

CONCLUSION

LINC01116/miR-9-5p plays a regulatory role in the progression of chordoma cells and is a potential biomarker for chordoma.

Effects of miR-9-5p on the migration, invasion and epithelial-mesenchymal transition process in cervical squamous cell carcinoma

OBJECTIVES

Cervical squamous cell carcinoma is the most common cancer in female reproductive system. This study aims to explore the effect of microRNA-9-5p (miR-9-5p) on the migration, invasion, and epithelial-mesenchymal transition (EMT) process of cervical squamous cells.

METHODS

Bioinformatics were used to predict the miRNAs that could bind to E-cadherin (E-cad). The Cancer Genome Atlas (TCGA) database was used to analyze and extract significantly differentially expressed miRNAs from part of cervical squamous cell carcinoma tissues and normal cervical tissues, and miR-9-5p was selected as the main research target. The translated regions (UTR) of wild-type E-cad (E-cad-WT 3'-UTR) or the 3'-UTR of mutant E-cad (E-Cad-MUT 3'-UTR) was transfected with miR-9-5p mimic normal control (NC), and miR-9-5p mimic was co-transfected human embryonic kidney cells (293T). The relationship between miR-9-5p and E-cad was detected by double luciferase assay. The expression of miR-9-5p in normal cervical epithelial cell lines (H8) and cervical squamous cell lines (C33A, siha, caski and Me180) were detected by quantitative real-time PCR. Then, the experiments were divided into groups as follows: a block control group, an overexpression control group (mimic-NC group), a miR-95p overexpression group (mimic group), an inhibitory expression control group (inhibitor-NC group), and a miR-9-5p inhibitory expression group (inhibitor group). The changes of migration ability were detected by scratch assay. Transwell invasion assay was used to analyze the changes of invasion ability, and the mRNA and protein changes of E-cad and vimentin were detected by quantitative real-time PCR and Western blotting.

RESULTS

MiR-9-5p had a targeting binding relationship with E-cad. Compared with the normal cervical tissue H8 cell line, the miR-9-5p was highly expressed in cervical cancer cell lines (C33A, siha, caski and Me180) (all P<0.05). The luciferase activity of E-cad-MUT was increased compared with that of E-cad-WT in miR-9-5p mimic cells (P<0.05). Compared with the blank control group, the protein and mRNA expressions of E-cad were decreased in the miR-9-5p mimic group (both P<0.05), which were increased in the miR-9-5p inhibitor group (both P<0.05). Compared with H8 cell line, the miR-9-5p was highly expressed in the cervical squamous cell lines (all P<0.05). Compared with the mimic-NC group, the distance of wound healing, the number of caski and Me180 cells invaded below the membrane, and the mRNA and protein expressions of vimentin were all increased in the miR-9-5p mimic group (all P<0.05), while the mRNA and protein of E-cad were decreased (both P<0.05). Compared with the inhibitor-NC group, the distance of wound healing, the number of caski and Me180 cells invading the membrane, and the mRNA and protein expressions of vimentin were decreased in the miR-9-5p inhibitor group (all P<0.05), but the mRNA and protein expressions of E-cad were increased (both P<0.05).

CONCLUSIONS

The miR-9-5p is highly expressed in cervical squamous cell carcinoma, which can increase the migration and invasion ability, and promote the EMT process of cancer cells.

The identification of N6-methyladenosine-related miRNAs predictive of hepatocellular carcinoma prognosis and immunotherapy efficacy

BACKGROUND

Hepatocellular carcinoma (HCC) has a high degree of malignancy and poor prognosis. N6-methyladenosine (m6A) modifications and microRNAs (miRNAs) play pivotal roles in tumorigenesis and development. However, the role of m6A-related miRNAs in HCC has not been clarified yet. This study aimed to identify the role of m6A-miRNAs in HCC prognosis through bioinformatics analysis.

METHODS

The clinicopathological information and RNA sequencing data of 369 HCC tumor tissues and 49 tumor-adjacent tissues were downloaded from the TCGA database. A total of 23 m6A regulators were extracted to evaluated the m6A-related miRNAs using Pearson's correlation analysis. Then, we selected prognosis-related m6A-miRNAs using a univariate Cox regression model and used the consensus cluster analysis to explore the characteristics of the m6A-miRNAs. The coefficient of the least absolute shrinkage and selection operator (LASSO) Cox regression was applied to construct a prognostic risk score model. The receiver operated characteristic (ROC) analysis was applied to evaluate the prognostic value of the signature. The biological functions of targeted genes were predicted by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Then, to validate the potential predictive value for prognosis, the miRNA expression profiles from the GSE76903 and GSE6857 were used. Single sample Gene Set Enrichment Analysis (ssGSEA) and Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) were applied to assess the immune microenvironment of HCC. Additionally, a meta-analysis was used to verify the prognostic value of the m6A-microRNAs. RT-PCR was applied to validated the expression of miRNAs in HCC tissues. Cell viability, transwell assay and RNA m6A dot blot assays of HCC cells was applied to access the function of miR-17-5p.

RESULTS

The expression of 48 m6A-related miRNAs was identified and 17 prognostic m6A-miRNAs was discovered. The expression profile of those 17 miRNAs was divided into three clusters, and these clusters were associated with the tumor microenvironment (TME) and prognosis. The nine m6A-related miRNA signature was associated with the prognosis of HCC, the AUC of the ROC was 0.771(TCGA dataset), 0.788(GSE76903) and 0.646(GSE6857). The TME and the expression of immune checkpoint molecules were associated with the risk score. The meta-analysis also validated the prognostic value of the m6A-related miRNAs (miR182-5p (HR:1.58, 95%CI:1.04-2.40) and miR-17-5p (HR:1.58, 95%CI: 1.04-2.40)). The expression of miR-17-5p was upregulated in HCC tissues and miR-17-5p showed an oncogenic role in HCC cells.

CONCLUSION

The clinical innovation is the use of m6A-miRNAs as biomarkers for predicting prognosis regarding immunotherapy response in HCC patients.

Interaction of miR-200a-3p with YAP regulates cell proliferation and metastasis differentially in HPV-positive and HPV-negative cervical cancer cells

BACKGROUND

Although evidence has revealed that miR-200a-3p is involved in the malignant progression of various tumors, the regulatory mechanism of miR-200a-3p in the development of cervical cancer (CC) cells with different HPV statuses remains unknown. The present study was to investigate the differential effects of either miR-200a-3p or YAP on tumorous cells' fate in vitro in HPV-negative and HPV-positive cervical cancer cell models, and to explore if the changes in proliferation, migration, and invasion of the CC cells with different HPV statuses could be attributed to the differential interactions between miR-200a-3p and YAP.

METHODS

The colony formation assays, EDU assays and Transwell assays were performed for CC cell proliferation, migration and invasion capacities analysis. The prediction of downstream targets of miR-200a-3p was performed by bioinformatical databases. The dual-luciferase reporter assays were used to validate the binding sites of miR-200a-3p and YAP. The qRT-PCR assays were performed to quantify the mRNA expression of miR-200a-3p and YAP, and the protein levels of YAP were examined by Western blot analysis.

RESULTS

The results demonstrated that miR-200a-3p overexpression suppressed proliferation, migration, and invasion of the HPV-negative C33A cells but promoted the growth and metastasis of HPV-positive CC cells, while YAP promoted the cell growth and metastasis not only in HPV-negative but also in the HPV-positive CC cells. The suppressive role of miR-200a-3p in C33A cells appeared to be mediated partially by direct interaction with YAP, and YAP might participate in miR-200a-3p-mediated cellular changes in CC cells differing from not only the presence or absence of HPV but even also the subtypes of HPV of CC cells. Meanwhile, we preliminarily revealed that the expression level of miR-200a-3p was significantly decreased in HPV-negative, but not in HPV16-positive cervical neoplasm mucus samples.

CONCLUSION

miR-200a-3p-mediated functional changes of YAP exhibited regulatory effects on cells' fate differentially in HPV-negative and HPV-positive cervical cancer cells.

The Role of MicroRNA in the Regulation of Tumor Epithelial–Mesenchymal Transition

Consistently, the high metastasis of cancer cells is the bottleneck in the process of tumor treatment. In this process of metastasis, a pivotal role is executed by epithelial–mesenchymal transition (EMT). The epithelial-to-mesenchymal transformation was first proposed to occur during embryonic development. Later, its important role in explaining embryonic developmental processes was widely reported. Recently, EMT and its intermediate state were also identified as crucial drivers in tumor progression with the gradual deepening of research. To gain insights into the potential mechanism, increasing attention has been focused on the EMT-related transcription factors. Correspondingly, miRNAs target transcription factors to control the EMT process of tumor cells in different types of cancers, while there are still many exciting and challenging questions about the phenomenon of microRNA regulation of cancer EMT. We describe the relevant mechanisms of miRNAs regulating EMT, and trace the regulatory roles and functions of major EMT-related transcription factors, including Snail, Twist, zinc finger E-box-binding homeobox (ZEB), and other families. In addition, on the basis of the complex regulatory network, we hope that the exploration of the regulatory relationship of non-transcription factors will provide a better understanding of EMT and cancer metastasis. The identification of the mechanism leading to the activation of EMT programs during diverse disease processes also provides a new protocol for the plasticity of distinct cellular phenotypes and possible therapeutic interventions. Here, we summarize the recent progress in this direction, with a promising path for further insight into this fast-moving field.

Perspectives of using microRNA-loaded nanocarriers for epigenetic reprogramming of drug resistant colorectal cancers

Epigenetic regulation by microRNAs (miRs) demonstrated a promising therapeutic potential of these molecules to regulate genetic activity in different cancers, including colorectal cancers (CRCs). The RNA-based therapy does not change genetic codes in tumor cells but can silence oncogenes and/or reactivate inhibited tumor suppressor genes. In many cancers, specific miRs were shown to promote or stop tumor progression. Among confirmed and powerful epigenetic regulators of colon carcinogenesis and development of resistance are onco-miRs, which include let-7, miR-21, miR-22, miR-23a, miR-27a, miR-34, miR-92, miR-96, miR-125b, miR-135b, miR-182, miR-200c, miR-203, miR-221, miR-421, miR-451, and others. Moreover, various tumor-suppressor miRs (miR-15b-5b, miR-18a, miR-20b, miR-22, miR-96, miR-139-5p, miR-145, miR-149, miR-197, miR-199b, miR-203, miR-214, miR-218, miR-320, miR-375-3p, miR-409-3p, miR-450b-5p, miR-494, miR-577, miR-874, and others) were found silenced in drug-resistant CRCs. Re-expression of tumor suppressor miR is complicated by the chemical nature of miRs that are not long-lasting compounds and require protection from the enzymatic degradation. Several recent studies explored application of miRs using nanocarrier complexes. This study critically describes the most successfully tested nanoparticle complexes used for intracellular delivery of nuclear acids and miRs, including micelles, liposomes, inorganic and polymeric NPs, dendrimers, and aptamers. Nanocarriers shield incorporated miRs and improve the agent stability in circulation. Attachment of antibodies and/or specific peptide or ligands facilitates cell-targeted miR delivery. Addressing in vivo challenges, a broad spectrum of non-toxic materials has been tested and indicated reliable advantages of lipid-based (lipoplexes) and polymer-based liposomes. Recent cutting-edge developments indicated that lipid-based complexes with multiple cargo, including several miRs, are the most effective approach to eradicate drug-resistant tumors. Focusing on CRC-specific miRs, this review provides a guidance and insights towards the most promising direction to achieve dramatic reduction in tumor growth and metastasis using miR-nanocarrier complexes.

Functional Screen for microRNAs Suppressing Anchorage-Independent Growth in Human Cervical Cancer Cells

The progression of anchorage-dependent epithelial cells to anchorage-independent growth represents a critical hallmark of malignant transformation. Using an in vitro model of human papillomavirus (HPV)-induced transformation, we previously showed that acquisition of anchorage-independent growth is associated with marked (epi)genetic changes, including altered expression of microRNAs. However, the laborious nature of the conventional growth method in soft agar to measure this phenotype hampers a high-throughput analysis. We developed alternative functional screening methods using 96- and 384-well ultra-low attachment plates to systematically investigate microRNAs regulating anchorage-independent growth. SiHa cervical cancer cells were transfected with a microRNA mimic library (n = 2019) and evaluated for cell viability. We identified 84 microRNAs that consistently suppressed growth in three independent experiments. Further validation in three cell lines and comparison of growth in adherent and ultra-low attachment plates yielded 40 microRNAs that specifically reduced anchorage-independent growth. In conclusion, ultra-low attachment plates are a promising alternative for soft-agar assays to study anchorage-independent growth and are suitable for high-throughput functional screening. Anchorage independence suppressing microRNAs identified through our screen were successfully validated in three cell lines. These microRNAs may provide specific biomarkers for detecting and treating HPV-induced precancerous lesions progressing to invasive cancer, the most critical stage during cervical cancer development.

Cervical Cancer, Papillomavirus, and miRNA Dysfunction

Cervical cancer is the leading cause of death by cancer in women from developing countries. Persistent infection with high-risk human papillomavirus (HPV) types 16 and 18 is a major risk factor for cervical carcinogenesis. Nevertheless, only a few women with morphologic expression of HPV infection progress into invasive disease suggesting the involvement of other factors in cervical carcinogenesis. MicroRNAs (miRNAs) are conserved small non-coding RNAs that negatively regulate gene expression including genes involved in fundamental biological processes and human cancer. Dysregulation of miRNAs has been widely reported in cervical cancer. This work focuses on reviewing the miRNAs affected during the HPV infection process, as well relevant miRNAs that contribute to the development and maintenance of malignant cervical tumor cells. Finally, we recapitulate on miRNAs that may be used to distinguish between healthy individuals from patients with precancerous lesions or cervical tumors.

RNA-based gene targeting therapies for human papillomavirus driven cancers

While platinum-based chemotherapy, radiation therapy and or surgery are effective in reducing human papillomavirus (HPV) driven cancer tumours, they have some significant drawbacks, including low specificity for tumour, toxicity, and severe adverse effects. Though current therapies for HPV-driven cancers are effective, severe late toxicity associated with current treatments contributes to the deterioration of patient quality of life. This warrants the need for novel therapies for HPV derived cancers. In this short review, we examined RNA-based therapies targeting the major HPV oncogenes, including short-interfering RNAs (siRNAs) and clustered regularly interspaced short palindromic repeats (CRISPR) as putative treatment modalities. We also explore other potential RNA-based targeting approaches such as microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and mRNA vaccines as future treatment modalities for HPV cancers. Some of these technologies have already been approved for clinical use for a range of other human diseases but not for HPV cancers. Here we explore the emerging evidence supporting the effectiveness of some of these gene-based therapies for HPV malignancies. In short, the evidence sheds promising light on the feasibility of translating these technologies into a clinically relevant treatment modality for HPV derived cancers and potentially other virally driven human cancers.

Knockdown of lncRNA NEAT1 suppresses proliferation and migration, and induces apoptosis of cervical cancer cells by regulating the miR‑377/FGFR1 axis

To investigate the role of NEAT1 and the microRNA (miR)-377/fibroblast growth factor receptor 1 (FGFR1) axis in cervical cancer (CC), the expression levels of NEAT1, FGFR1 and miR-377 were detected in CC tissues and cell lines. NEAT1 or FGFR1 was knocked down by transfection with short hairpin RNA (sh)-NEAT1 or sh-FGFR1, and miR-377 was overexpressed by transfection with miR-377 mimics in HeLa and C33A cells. Cell viability and migration were measured using MTT and Transwell assays, respectively. Cell apoptosis was determined by flow cytometry. A dual luciferase reporter assay was performed to confirm the presence of binding sites between miR-377 and FGFR1. The results revealed that the expression levels of NEAT1 and FGFR1 were significantly elevated, whereas miR-377 expression was markedly decreased in CC tissues and cell lines. In HeLa and C33A cells, after NEAT1 knockdown, miR-377 expression was increased, cell viability and migration were inhibited, and apoptosis was induced. Similarly, silencing FGFR1 inhibited cell viability and migration, and induced apoptosis of HeLa and C33A cells. A dual luciferase reporter gene assay verified a targeting relationship between NEAT1 and miR-377. Inhibition of miR-377 or overexpression of FGFR1 reversed the effects of NEAT1 knockdown on cell function in HeLa and C33A cells. Moreover, a dual luciferase reporter assay confirmed that FGFR1 was a direct target of miR-377. In conclusion, suppression of NEAT1 inhibited cell viability and migration, and promoted apoptosis of CC cells, and these effects were achieved through regulation of the miR-377/FGFR1 axis.

The dual role of microRNA-9 in gastrointestinal cancers: oncomiR or tumor suppressor?

microRNA are noncoding endogenous RNAs of ∼ 25-nucleotide, involved in RNA silencing and controlling of cell function. Recent evidence has highlighted the important role of various in the biology of human cancers. miR-9 is a highly conserved microRNA and abnormal regulation of miR-9 expression has various impacts on disease pathology. miR-9 may play a dual tumor-suppressive or oncomiR activity in several cancers. There have been conflicting reports concerning the role of miR-9 in gastrointestinal cancers. Several signaling pathways including PDK/AKT, Hippo, Wnt/β-catenin and PDGFRB axes are affected by miR-9 in suppressing proliferation, invasion and metastasis of tumor cells. Oncogenic miR-9 triggers migration, metastasis and clinic-pathological characteristics of patients with gastrointestinal malignancy by targeting various enzymes and transcription factors such as E-cadherin, HK2, LMX1A, and CDX2. On the other hand, long non-coding RNAs and circular RNAs can modulate miR-9 expression in human cancers. In this review, we aimed to summarize recent findings about the potential value of miR-9 in gastrointestinal tumors, that include: screening, prognostic and treatment.

Methylation-associated silencing of miR-9-1 promotes nasopharyngeal carcinoma progression and glycolysis via HK2

Characteristically, cancer cells metabolize glucose through aerobic glycolysis, known as the Warburg effect. Accumulating evidence suggest that during cancer formation, microRNAs (miRNAs) could regulate such metabolic reprogramming. In the present study, miR‐9‐1 was identified as significantly hypermethylated in nasopharyngeal carcinoma (NPC) cell lines and clinical tissues. Ectopic expression of miR‐9‐1 inhibited NPC cell growth and glycolytic metabolism, including reduced glycolysis, by reducing lactate production, glucose uptake, cellular glucose‐6‐phosphate levels, and ATP generation in vitro and tumor proliferation in vivo. HK2 (encoding hexokinase 2) was identified as a direct target of miR‐9‐1 using luciferase reporter assays and Western blotting. In NPC cells, hypermethylation regulates miR‐9‐1 expression and inhibits HK2 translation by directly targeting its 3' untranslated region. MiR‐9‐1 overexpression markedly reduced HK2 protein levels. Restoration of HK2 expression attenuated the inhibitory effect of miR‐9‐1 on NPC cell proliferation and glycolysis. Fluorescence in situ hybridization results indicated that miR‐9‐1 expression was an independent prognostic factor in NPC. Our findings revealed the role of the miR‐9‐1/HK2 axis in the metabolic reprogramming of NPC, providing a potential therapeutic strategy for NPC.

miR-9-5p promotes wear-particle-induced osteoclastogenesis through activation of the SIRT1/NF-κB pathway

To explore the potential function of miR-9-5p in wear-particle-induced osteoclastogenesis, we examined the expression of SIRT1 and miR-9-5p in particle-induced osteolysis (PIO) mice calvariae and polyethylene (PE)-induced RAW 264.7 cells and found that SIRT1 expression was downregulated while miR-9-5p expression was upregulated in both models. We then verified that miR-9-5p targets SIRT1. miR-9-5p was found to promote PE-induced osteoclast formation from RAW 264.7 cells by tartrate-resistant acid phosphatase staining and detection of osteoclast markers, and miR-9-5p activation of the SIRT1/NF-kB signaling pathway was found in cells by detecting the expression of SIRT1/NF-kB pathway-related proteins and rescue assays. In conclusion, we found that miR-9-5p activated the SIRT1/NF-κB pathway to promote wear-particle-induced osteoclastogenesis. miR-9-5p may be a useful therapeutic target for PIO remission and treatment.

Interplay between SOX9 transcription factor and microRNAs in cancer

SOX transcription factors are critical regulators of development, homeostasis and disease progression and their dysregulation is a common finding in various cancers. SOX9 belongs to SOXE family located on chromosome 17. MicroRNAs (miRNAs) possess the capacity of regulating different transcription factors in cancer cells by binding to 3'-UTR. Since miRNAs can affect differentiation, migration, proliferation and other physiological mechanisms, disturbances in their expression have been associated with cancer development. In this review, we evaluate the relationship between miRNAs and SOX9 in different cancers to reveal how this interaction can affect proliferation, metastasis and therapy response of cancer cells. The tumor-suppressor miRNAs can decrease the expression of SOX9 by binding to the 3'-UTR of mRNAs. Furthermore, the expression of downstream targets of SOX9, such as c-Myc, Wnt, PI3K/Akt can be affected by miRNAs. It is noteworthy that other non-coding RNAs including lncRNAs and circRNAs regulate miRNA/SOX9 expression to promote/inhibit cancer progression and malignancy. The pre-clinical findings can be applied as biomarkers for diagnosis and prognosis of cancer patients.

Dysregulated LncRNAs Act as Competitive Endogenous RNAs and Are Associated With Cervical Cancer Development in UYGHUR Women

Cervical cancer is one of the most malignant tumors in women, particularly those in rural and remote areas. Its underlying molecular mechanisms, including the functions of non-coding RNA (ncRNAs), require more extensive investigation. In this study, high throughput transcriptome sequencing (RNA-seq) was used to identify differentially expressed lncRNAs and mRNAs in normal, cervical intraepithelial neoplasia and cervical cancer tissues from Uyghur women in western China. Dysregulated lncRNAs were found to extensively participate in cervical cancer development, including viral carcinogenesis, cell cycle and cytokine-cytokine receptor signaling. Two miRNA-host lncRNAs, LINC00925 and MIR155HG, showed elevated expression in cervical cancer samples, but prolonged the survival time of cervical cancer patients. The 2 mature miRNAs of the above 2 lncRNAs, miR-9 and miR-155, also showed similar features in cervical cancer. In addition, we identified 545 lncRNAs with potential functions in regulating these 2 miRNAs as competing endogenous RNAs (ceRNAs). In summary, our study demonstrated the dysregulated lncRNAs/miRNAs, particularly LINC00925/miR-9 and MIR155HG/miR-155, regulate the development of cervical cancer by forming a interaction network with mRNAs, highlighting the importance of elucidating the underlying mechanisms of ncRNAs in cervical cancer development.

MiR-9-5p promotes cell proliferation and migration of hepatocellular carcinoma by targeting CPEB3

Objective: This study aimed to observe the effect of miR-9-5p and CPEB3 on hepatocellular carcinoma (HCC) cells, and investigate the underlying targeting regulatory mechanism. Materials & methods: Various experiments like CCK-8, colony formation assay, wound healing assay and Transwell were performed for cancer cell activities detection, including cell proliferation, growth activity, migration and invasion. Results: MiR-9-5p was found to be highly expressed in HCC cells, while CPEB3 was poorly expressed (p < 0.05). The overexpression of miR-9-5p and the silencing of CPEB3 both could significantly promote cell proliferation, migration and invasion (p < 0.05). In addition, miR-9-5p could target to downregulate CPEB3 expression, thus accelerating cell proliferation, migration, invasion and epithelial-mesenchymal transition process in HCC. Conclusion: MiR-9-5p can target CPEB3, thereby promoting cell proliferation, migration and invasion in HCC. The axis of miR-9-5p/CPEB3 is expected to become a potential therapeutic target beneficial for HCC patients.

The interplay between non-coding RNAs and Twist1 signaling contribute to human disorders

Twist-related protein 1 (Twist1) is a basic helix-loop-helix (bHLH) transcription factor (TF) being coded by the TWIST1 gene. This TF has a fundamental effect on the normal development and in the pathogenesis of various diseases especially cancer. Twist1 has interactions with some long non-coding RNAs and miRNAs. The interactions between this TF and various miRNAs such as miR-16, miR-26b-5p, miR-1271, miR-539, miR-214, miR-200b/c, miR-335, miR-10b, and miR-381 are implicated in the carcinogenic processes. TP73-AS1, LINC01638, ATB, NONHSAT101069, CASC15, H19, PVT1, LINC00339, LINC01385, TANAR, SNHG5, DANCR, CHRF, and TUG1 are among long non-coding RNAs which interact with Twist1 and participate in the carcinogenesis. This review aims at depicting the interaction between these non-coding transcripts and Twist1 and the consequence of these interactions in human neoplasms.

Circular RNA circNFATC3 acts as a miR-9-5p sponge to promote cervical cancer development by upregulating SDC2

PURPOSE

Circular RNAs (circRNAs) constitute a class of regulatory RNAs that are thought to play important roles in tumor initiation and progression. Several studies have reported that circRNAs may be involved in various biological processes via networks of competing endogenous RNAs (ceRNAs). However, the regulatory roles and underlying mechanisms of circRNAs in cervical cancer (CC) still largely remain to be resolved.

METHODS

CircNFATC3 (hsa_circ_0005615) expression was assessed in CC cell lines (SiHa, H8) using circRNA microarray analysis, whereas qRT-PCR was used to detect circNFATC3 and miR-9-5p expression in primary human CC tissues and cell lines. The tumor promoting role of circNFATC3 was verified in CC cells using a series of functional assays, and interactions between circNFATC3, miR-9-5p and syndecan-2 (SDC2) were investigated using dual-luciferase reporter assays. SDC2 protein expression was detected using Western blotting and immunohistochemistry. The tumor promoting role of circNFATC3 was confirmed in vivo using a CC xenograft model.

RESULTS

We found that circNFATC3 expression was upregulated in primary CC tissues and positively correlated with CC tumor size and stromal invasion. In addition, we found that exogenous circNFATC3 overexpression enhanced the proliferation, migration and invasion of HeLa cells, while its knockdown reduced the malignancy of SiHa cells. We also found that circNFATC3 may act directly as a miR-9-5p sponge to regulate SDC2 expression and its downstream signaling pathways, thereby enhancing CC development.

CONCLUSION

Our data indicate that circNFATC3 sponges miR-9-5p to regulate SDC2 expression and, thereby, to promote CC tumor development.

miR-326 inhibits the cell proliferation and cancer stem cell-like property of cervical cancer in vitro and oncogenesis in vivo via targeting TCF4

Background

Cervical cancer ranks as one of the most prevalent female malignancies globally, and its treatment with new targets has been the focus of current research. The present study set out to investigate the function of microRNA-326 (miR-326) in vitro and in vivo and to verify the direct targeting of transcription factor 4 (TCF4) by miR-326.

Methods

The detection of messenger RNA (mRNA) expressing miR-326 and TCF4 in cervical cancer cell lines and tumor samples was conducted using quantitative real-time polymerase chain (qRT-PCR). A dual-luciferase reporter assay was carried out to detect the target relationship of miR-326 with TCF4. A Cell Counting Kit-8 (CCK-8) assay was employed to detect the effect of miR-326 on CasKi cell viability. Flow cytometry and western blotting were employed to examine the effects of miR-326 on cancer stem cell (CSC)-like property. Tumor weight was measured in orthotopic xenograft mouse models. Immunohistochemistry was employed to analyze the protein expression levels of Ki-67, proliferating cell nuclear antigen (PCNA), CD44, and SRY-box 4 (SOX4).

Result

Downregulation of the mRNA expression levels of miR-326 was observed in cervical cancer cell lines and tumor tissue, while the levels of TCF4 were upregulated. The dual-luciferase reporter assay revealed binding of miR-326 to the three prime untranslated region (3'-UTR) of TCF4. In vitro assays demonstrated that miR-326 inhibited CasKi cell proliferation through regulating TCF4. miR-326 also suppressed the CSC-like property of CasKi cells by targeting TCF4. Furthermore, the protein expression levels of cyclin D1, β-catenin, and c-Myc were decreased when miR-326 was added to TCF4-transfected cells. In vivo assays demonstrated that miR-326 inhibited tumor weight, growth, and the protein expression levels of Ki-67, PCNA, CD44, SOX4, and β-catenin.

Conclusions

miR-326 acted in a tumor-suppressive manner through its regulation of TCF4, and has potential as a biomarker or therapeutic target for cervical cancer.

MiR-139-5p-ZEB1 is a Molecular Regulator of Growth, Invasion, and Epithelial-to-Mesenchymal Transition of Cervical Cancer

Objective

To verify that miR-139-5p-zinc finger E-box-binding homeobox 1 (ZEB1) is a molecular regulator of the biological function and epithelial–mesenchymal transition (EMT) of cervical cancer (CC) cells.

Methods

Cancerous tissues, corresponding paracancerous tissues, and serum were sampled from patients with CC. MiR-139-5p and ZEB1 in tissue specimens, serum specimens, and purchased CC cell lines were quantified, and Pearson correlation coefficient was adopted for correlation analysis of miR-139-5p in clinical specimens. Receiver operating characteristic (ROC) curves were adopted to analyze the diagnostic value of miR-139-5p and ZEB1 for CC. The expression of genes in CC cells was changed by transfection. The proliferation, colony formation, invasion, and apoptosis of cells were determined, and the protein level of EMT markers (N-cadherin, vimentin, and E-cadherin) was also quantified. Moreover, the targeting relationship between miR-139-5p and ZEB1 was determined.

Results

Our data showed that the expression of miR-139-5p decreased greatly in CC tissues, and it also significantly decreased in the serum, while the expression of serum ZEB1 was opposite. In addition, the miR-139-5p expression in CC tissues was positively correlated with that in serum, while serum miR-139-5p was negatively correlated with serum ZEB1. The areas under the curves (AUCs) of the two for identifying CC were 0.923 and 0.890, respectively. Both up-regulation of miR-139-5p and down-regulation of ZEB1 suppressed the colony formation, proliferation, invasion, and EMT of CC cells, and intensified their apoptosis. Moreover, miR-139-5p negatively regulated the transcription of ZEB1, and down-regulation of the former could reverse the molecular regulatory effects of down-regulating ZEB1 on the above biological behaviors of CC cells.

Conclusion

The above data imply that miR-139-5p-ZEB1 axis may be the key to curbing the progression of CC.

linc00968 inhibits the tumorigenesis and metastasis of lung adenocarcinoma via serving as a ceRNA against miR-9-5p and increasing CPEB3

Increasing evidence confirms that long noncoding RNAs (lncRNAs) exert vital functions in multiple biological process among malignant cancers. In the current study, we uncovered that linc00968 was downregulated in lung adenocarcinoma (LUAD). Furthermore, the low level of linc00968 was correlated with worse prognosis in patients with LUAD. Upregulation of linc00968 restrained the growth and metastatic phenotypes of LUAD cell in vitro and in vivo. Using bioinformation methods and luciferase reporter assay, we identified that linc00968 acted as a competing endogenous RNA (ceRNA) via sponging miR-9-5p to modulate the level of Cytoplasmic Polyadenylation Element Binding Protein 3 (CPEB3) in LUAD. In addition, LUAD cell migration, colony formation and epithelial-mesenchymal transition (EMT) process were suppressed by linc00968 while these aggressive traits were reversed by miR-142-5p or CPEB3 silencing. Altogether, our work disclosed that linc00968 played a critical role in LUAD and linc00968/miR-9-5p/CPEB3 regulatory axis might be a potential treatment target in LUAD.

Connecting METTL3 and intratumoural CD33+ MDSCs in predicting clinical outcome in cervical cancer

Background

Methyltransferase-like 3 (METTL3) is a member of the m⁶A methyltransferase family and acts as an oncogene in cancers. Recent studies suggest that host innate immunity is regulated by the enzymes controlling m⁶A epitranscriptomic changes. Here, we aim to explore the associations between the levels of METTL3 and CD33⁺ myeloid-derived suppressor cells (MDSCs) in tumour tissues and the survival of patients with cervical cancer (CC).

Methods

Specimens of paraffin embedded tumour from 197 CC patients were collected. The expression levels of METTL3 and CD33 were measured by immunohistochemical (IHC) staining. The clinical associations of the IHC variants were analysed by Pearson’s or Spearman’s chi-square tests. Overall survival (OS) and disease-free survival (DFS) were estimated by the Kaplan–Meier method and log-rank test. Hazard ratios (HRs) and independent significance were obtained via Cox proportional hazards models for multivariate analyses. METTL3 in CD33⁺ cells or CC-derived cells was knocked down by METTL3-specific siRNA, and MDSC induction in vitro was performed in a co-culture system in the presence of METTL3-siRNA and METTL3-knockdown-CC-derived cells compared with that of the corresponding controls.

Results

We found that tumour tissues displayed increased levels of METTL3 and CD33⁺ MDSCs compared with tumour-adjacent tissues from the same CC patients. Importantly, METTL3 expression was positively related to the density of CD33⁺ cells in tumour tissues (P = 0.011). We further found that the direct CD33⁺CD11b⁺HLA-DR⁻ MDSC induction and tumour-derived MDSC induction in vitro were decreased in the absence of METTL3. The level of METTL3 in tumour microenvironments was significantly related to advanced tumour stage. The levels of METTL3 and CD33⁺ MDSCs in tumour tissues were notably associated with reduced DFS or OS. Cox model analysis revealed that the level of METTL3 in tumour cells was an independent factor for patient survival, specifically for DFS (HR = 3.157, P = 0.022) and OS (HR = 3.271, P = 0.012), while the CD33⁺ MDSC number was an independent predictor for DFS (HR: 3.958, P = 0.031). Interestingly, in patients with advanced-disease stages (II–IV), METTL3 in tumour cells was an independent factor for DFS (HR = 6.725, P = 0.010) and OS (HR = 5.140, P = 0.021), while CD33⁺ MDSC density was an independent factor for OS (HR = 8.802, P = 0.037).

Conclusion

Our findings suggest that CD33⁺ MDSC expansion is linked to high levels of METTL3 and that METTL3 and CD33⁺ MDSCs are independent prognostic factors in CC.